1. Technical Field
The present invention relates to a two-liquid coagulation type ink set for inkjet recording and a method of image recording using the same.
2. Background Art
As a medium for inkjet recording, various recording media have been studied. A technology which enables the achievement of high quality images even with commercially available plain paper has been required. In addition, for ink as well, studies have been carried out regarding color materials like a pigment, etc. as an ink material which can be used for obtaining resistance to water and light.
However, when recording is carried out by using plain paper, sometimes there are cases in which blurring is too great to obtain image density and fixing property at a sufficient level. In particular, the demand for achieving high speed is great in inkjet recording, and therefore, suitability for recording is required in the case where high speed recording is performed in a single pass manner, by which recording can be carried out with a single operation of a head, rather than in a shuttle scanning manner.
When images are formed on various recording media, as a way of obtaining a high fixing property, broadening of a range for reproducing secondary colors, maintenance of optical density during high speed printing and prevention of blurring, a method of using two kinds of liquids comprising a first liquid containing pigment particles and a second liquid containing a liquid composition for improving printability has been suggested (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2007-261206). According to this method, it is suggested that the above described goals can be achieved by reducing the particle diameter of the pigment included in the first liquid, specifically, by reducing the content ratio of coarse particles which have a diameter of 150 nm or more.
In addition, there is also disclosure of a method of producing a liquid composition, wherein polymer pigment fine particles having a small average particle diameter and high size uniformity are contained in a dispersed state (for example, see JP-A No. 2007-119586). According to this disclosure, a method of recording by using a first liquid is mainly described, and with respect to a process for fixing an image by using a second liquid which is different from the colored liquid composition, a method using a polyvalent cation is described.